Patent GB-190322372-A (GB)
Title: Improvements in Fluid Pressure Brake Mechanism.
Inventor: CORRINGTON MURRAY
Filed: 1903-10-16
Granted: 1903-11-19
Abstract: 22,372. Corrington, M. Oct. 16. Brakes.-The engineer's brake valve is fitted with a subsidiary valve so that the brakes may be applied on the engine only, or on the cars only, or on the engine and on the cars alternately or continuously. The valve shown in Fig. 1 is made in four sections 1, 2, 3, 4, and is connected at 8 to the main reservoir or pump, at 9 to the trainpipe, at 20 to the brake cylinder, and at 21 to the auxiliary reservoirs. The upper section 4 contains the main brake valve 55, Figs. 1 and 2, and the auxiliary valve 71, which are operated by handles 62, 73 respectively. When the valve 55 is moved to the position shown in Fig. 1, the fluid under pressure flows through the nozzle 8 and passage 65 to the rotary valve 55, passing through it and the passages 42,43, 44 to the train-pipe connection 9 and to the chambers containing the pistons 10,31. The pressure on the piston 31 is equalized by fluid passing through the passages 48, 57, and 47 to its upper side, and the piston 10 is forced down until the fluid flows through the recess 23 to the chamber containing the valves 12, 13, and thence through the nozzle 21 to the auxiliary reservoir. The fluid also flows through a port 52, Fig. 5, in the edge of the seat of the valve 55, Fig. 1, and through a reducing-valve 66 and the passage 53 to the chamber above the small valve 71, Fig. 2. The handle 62, Fig. 1, has six positions, in which it is held by a spring catch 63. In the first position, the ports 56, 42 are coincident, as described above, the brakes being released. In the second position, the port 56 is over the port 45, Fig. 5, and the fluid flows through a reducing-valve and the port 50 to the train-pipe. In the third position, the ports 46, 56 are coincident, and the pressure flows through a reducing-valve to the passage 51 and the train-pipe. In these three positions, the curved part of the cavity 57, shown in plan in Fig. 6, keeps open the passage 47, Fig. 1, connecting the passage 43 and the chamber containing the piston 31. In the fourth or " lap " position, all the ports are closed. In the fifth position, the cavity 57 connects the passage 47 to the small preliminary-exhaust port 49, Fig. 5, thus releasing the pressure above the piston 31. Five to ten pounds having thus been let off, the valve 55, Fig. 1, is returned to tne lap position, when the train-pipe pressure beneath the piston 31 lifts it and flows through the passage 33 and cock 34 to the atmosphere, until the pressure below the piston 31 is slightly less than that above it. The piston then descends slowly, and closes the port 33. This is the common service application of the brakes. In the sixth or " emergency " position of the valve 55, the cavity 58, Fig. 6, connects the port 42 with the exhaust port 41, Fig. 5, exhausting the air rapidly, and effecting the "emergency" operation of the triple valves on the train. The auxiliary valve 71, Fig. 2, may be moved into four positions ; in the normal position, the cavity 76 connects the ports 77, 78 ; in the " lap " position, all the ports are closed in the "application" position, the passage 75 stands over a passage 79, which leads the compressed fluid through the passage 20, Fig. 1, to the brake cylinders. In the " release position, the cavity 76, Fig. 2, connects the passage 79 to the exhaust passage 77. In the usual service application of the brakes, as described above, the piston 10, Fig. 1, moves upwards until the spring stop 14 strikes the bottom of the section 2, the piston first opening the graduating-valve 13, and then moving the valve 12 until the ports 18, 22 are coincident, thus admitting to the brake cylinder compressed fluid from the auxiliary reservoir. In an "emergency " application, the spring of the stop 14 yields, and the valve 12 is drawn across and clear of the port 18, leaving clear the passage between the brakecylinder connection 20 and the auxiliary-reservoir connection 21. In releasing the brakes, the air is admitted to the train-pipe, and the piston 10 and valve 12 move down so as to connect the ports 18,19, when the air from the brake cylinder flows through them and through the passage 78 to the supplementary valve 71, Fig. 2, and thence through the port 77 to the atmosphere. The auxiliary reservoir is then re-charged, the triple valves on the cars moving to release the brakes meanwhile. To hold the engine brakes on and to re-charge the auxiliary reservoir meanwhile, the valve 71, Fig. 2, is moved to the "lap position, cutting off the connection between the ports 77, 78, just before operating the handle 62 to release the car brakes. An extra reservoir may be used with the brake cylinder on the tender. In a modification, which enables the car brakes to be applied before the engine brakes, the passage 78, Figs. 1, 2, 5, the port 19, and the D-cavity of the valve 12, are omitted ; the valve 12 may be omitted entirely, only a flat graduating-valve 13 for the port 18 being fitted. The valve 71 and its seat are modified to suit this construction. When the valve 55 is in a normal position, the piston 10 is lifted and the port 18 opened by a reduction of the pressure in the train-pipe, so that the brakes are applied if the pipe bursts, or if the train breaks in two. In another modification for enabling the car brakes to be applied first, the chamber containing the piston 10 is not connected directly to the passage 43 and the train-pipe, but a passage is formed in the side of the port 42 and is led up to the auxiliary valve 71, through which the air normally passes to another passage leading downwards to the upper part of the piston chamber, and thus, if the valve 71 is turned suitably, the chamber is cut off, so that the valve 13 and the engine brakes are not operated when the car brakes are applied. The valves 55, 71 enable the engineer to increase or diminish at will the pressure in the brake cylinders. The apparatus may be used on any steam railway engine or locomotive, or on a trolley car, or on any other car or vehicle for carrying freight or passengers, whether driven by its own electrical or other motors, or drawn by another vehicle.